Turfgrass Epistemology

S3 E62 Dr. Lee Miller - Turf Fungicide Resistance?

In this episode of Turfgrass Epistemology, I sit down with Dr. Lee Miller of Purdue University, one of the leading experts in turfgrass pathology, to break down everything you need to know about turfgrass disease resistance, fungicide rotations, and accurate turf disease identification. Whether you manage golf course greens, sports fields, or home lawns, this conversation gives you the practical, science-based guidance needed to protect your turf from common and emerging diseases.
We explore what disease resistance in turfgrass truly means, why resistance develops, and how environmental conditions and management practices influence disease pressure. Dr. Miller explains how to design effective fungicide rotation programs, how to avoid resistance through proper FRAC group management, and how to choose the right mode of action at the right time of year.
If you’re looking for evidence-based turfgrass management, best practices for fungicide use, or expert insights into turf disease diagnostics, this video delivers the tools you need.
Subscribe for more science-driven conversations on turfgrass health, management, and critical thinking.
🎓 Turfgrass Epistemology — How do we know what we know?
📌 https://www.gofundme.com/f/TurfgrassEpistemology
Thank you for being part of this community and for supporting evidence-based turfgrass science.
Join Turfgrass Epistemology to get access to perks:https://www.youtube.com/channel/UC-UZnHkJhAmARDZ4YoHnc_A/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf
Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

S3 E61 Fungicides and Species Resistances Affects Dollar Spot

In this video, I analyze the 2025 Zhang et al. study on how fungicide scheduling and bentgrass cultivar resistance interact to influence dollar spot control. This research provides some of the strongest evidence to date that curative, damage-threshold-based fungicide programs can dramatically reduce inputs—up to 78 percent in certain cases—when paired with disease-resistant bentgrass cultivars. I explain how the researchers designed the field trials, what the low damage threshold means in practice, how 24-hour and next-application-day schedules performed differently, and why resistant cultivars such as Declaration produced such large savings without sacrificing control. I also discuss how inoculation affected disease pressure, why susceptible cultivars behaved differently, and what this means for superintendents trying to reduce fungicide use while maintaining high-quality fairways. If you want a clear, evidence-based explanation of how timing, cultivar resistance, and disease pressure shape fungicide performance, this video brings the science into focus.
🎓 Turfgrass Epistemology — How do we know what we know?
📌 https://www.gofundme.com/f/TurfgrassEpistemology
Thank you for being part of this community and for supporting evidence-based turfgrass science.
Join Turfgrass Epistemology to get access to perks:https://www.youtube.com/channel/UC-UZnHkJhAmARDZ4YoHnc_A/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf
Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

S3 E60 Biology and Management of Dollar Spot

In this video, I break down one of the most influential papers ever written on turfgrass pathology: Walsh, Ikeda, and Boland’s 1999 review on the biology and management of dollar spot. This paper remains a foundational resource for understanding how the pathogen operates, why the disease is so persistent on cool-season turf, and which management strategies are supported by evidence rather than tradition. I walk through the key sections of the paper, including the pathogen’s life cycle, the environmental conditions that drive epidemics, the role of cultural practices, and the strengths and weaknesses of common fungicide approaches. I also explain how the scientific understanding of dollar spot has progressed since 1999 and why many of the insights in this article still guide modern management decisions. If you work in turf management or simply want to understand the science behind one of the most costly diseases in the industry, this video will help you separate evidence from assumption and improve your decision-making.
🔬 Keywords: Dollar Spot, Bentgrass, Dew Removal, Nitrogen, Turfgrass Disease, Integrated ManagementDon’t forget to like, share, and subscribe to stay updated on more science-driven insights!
Become a member of Turfgrass Epistemology and support turfgrass research:www.youtube.com/@TurfgrassEpistemology/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf

S3 E59 Tinfoil Turfgrass: Don't Use This Soil Test!

In this episode of Turfgrass Epistemology, I review a popular lawn-care website article and an accompanying YouTube video that teach homeowners how to interpret a soil test that is, in reality, scientifically invalid for making nutrient decisions. These resources look polished and authoritative, but the advice they provide is fundamentally flawed — and following it can lead to unnecessary product applications, wasted money, and incorrect assumptions about soil health.
I’ll walk through both the website and the video step-by-step and explain:
Why the soil test they promote is not valid for nutrient recommendationsHow certain companies use oversimplified or misleading soil interpretations to sell productsThe scientific standards for a real soil test and what makes it trustworthyHow proper soil testing differs from marketing-driven “DIY” interpretationsWhat homeowners should actually look for when deciding if their lawn needs fertilizer, lime, or amendmentsHow to evaluate online lawn-care information and avoid advice that is not evidence-based
The goal of this video isn’t to criticize people — it’s to highlight why bad testing leads to bad decisions, and how to empower homeowners with the ability to recognize valid, science-based soil information.
If you’ve ever wondered whether the soil advice you see online is trustworthy, or how to distinguish real science from clever marketing, this episode will give you a clear, reliable framework for making informed choices.
🔬 Keywords: Dollar Spot, Bentgrass, Dew Removal, Nitrogen, Turfgrass Disease, Integrated ManagementDon’t forget to like, share, and subscribe to stay updated on more science-driven insights!
Become a member of Turfgrass Epistemology and support turfgrass research:www.youtube.com/@TurfgrassEpistemology/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf

S3 E58 Which Journals Can You Trust?

Not all scientific journals are created equal. Some exist to advance knowledge — others exist to collect publishing fees. In this episode of Turfgrass Epistemology, we explore how to tell the difference.
I’ll walk through the refereed process and explain how it differs from standard peer review, why that distinction matters, and how the structure of editorial oversight determines the credibility of the science that reaches the public. We’ll also take a close look at predatory journals — publications that mimic legitimate science while bypassing or corrupting the review process in exchange for author fees.
But the story isn’t as simple as “good” versus “bad.” Even in a predatory journal, a paper may contain sound science — the key is learning how to weigh the evidence and evaluate quality for yourself. We’ll discuss:
What defines a refereed journal versus a peer-reviewed one.
How to spot red flags in a publication or website.Why impact factors and indexing are useful but not foolproof.The difference between open access done right and pay-to-publish exploitation.Practical ways any reader — scientist or not — can assess a journal’s credibility.
By the end, you’ll have a framework for evaluating whether a journal’s claims deserve your trust — and how to apply critical thinking before citing, sharing, or believing “published” results.
If you care about how we know what we know, and why evidence must be judged as well as gathered, this episode is for you.
🎓 Turfgrass Epistemology — How do we know what we know?
📌 https://www.gofundme.com/f/TurfgrassEpistemology
Thank you for being part of this community and for supporting evidence-based turfgrass science.
Join Turfgrass Epistemology to get access to perks:https://www.youtube.com/channel/UC-UZnHkJhAmARDZ4YoHnc_A/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf
Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

S3 E57 Does Trinexapac Reduce Dollar Spot?

In this episode of Turfgrass Epistemology, we take a close look at one of the most frequently cited studies in turfgrass pathology — Golembiewski and Danneberger’s 1998 Agronomy Journal paper exploring how trinexapac-ethyl (TE) and nitrogen fertility influence the severity of dollar spot (Sclerotinia homoeocarpa) in creeping bentgrass.
The researchers found that TE, a popular plant growth regulator, didn’t increase disease as many feared — in fact, it reduced dollar spot when combined with adequate nitrogen. This discovery challenged the prevailing assumptions of the time and suggested that growth regulation and fertility could work together to reduce fungicide reliance on golf course fairways.
In this discussion, we unpack:
The experimental design and methodology behind the study.
Why mowing height and growth regulation changed disease outcomes.
How nitrogen rate influenced both dollar spot suppression and thatch accumulation.
What this means for modern integrated pest management (IPM) strategies in turfgrass systems.
By the end, we’ll consider whether the mechanisms observed in 1998 still hold true today — and what this research can teach us about evidence-based turf management in the age of marketing claims and quick fixes.
If you enjoy videos that bridge science, history, and turf management, consider subscribing and joining the conversation.
Paper discussed:Golembiewski, R. C., & Danneberger, T. K. (1998). Dollar spot severity as influenced by trinexapac-ethyl, creeping bentgrass cultivar, and nitrogen fertility. Agronomy Journal, 90(4), 466–470. https://doi.org/10.2134/agronj1998.00021962009000040004x
🔬 Keywords: Dollar Spot, Bentgrass, Dew Removal, Nitrogen, Turfgrass Disease, Integrated ManagementDon’t forget to like, share, and subscribe to stay updated on more science-driven insights!
Become a member of Turfgrass Epistemology and support turfgrass research:www.youtube.com/@TurfgrassEpistemology/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf

S3 E56 University Extension Programs

In this episode, I sit down to talk about a topic that’s been at the heart of American higher education for more than a century — university extension. We’ll explore how extension began, why it was once the lifeblood of land-grant universities, and how the system that connected science to society is now quietly disappearing.
Extension was created so universities could serve the public — not just by publishing papers, but by helping real people solve real problems. For decades, that mission worked. Faculty were rewarded for outreach, and industries like turfgrass, horticulture, and agriculture thrived because science and practice were linked. But somewhere along the way, the incentives changed. Grants, graduate students, and publication counts became the metrics of success, and the outreach mission — the reason land-grant universities existed in the first place — started to fade.
In this conversation, I reflect on when that shift began, what caused it, and what’s been lost in the process. We’ll talk about why extension matters, how it can be revitalized, and what universities risk when they stop valuing public service. My goal isn’t nostalgia — it’s to remind us that progress and connection don’t have to be opposites.
🎙️ Episode title: The Rise and Fall of University Extension🏛️ Topics: Smith-Lever Act history, land-grant universities, extension faculty, university incentives, outreach, and public service
📌 https://www.gofundme.com/f/TurfgrassEpistemology
Thank you for being part of this community and for supporting evidence-based turfgrass science.
Join Turfgrass Epistemology to get access to perks:https://www.youtube.com/channel/UC-UZnHkJhAmARDZ4YoHnc_A/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf
Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

S3 E55 Dew, Nitrogen, and Dollar Spot

Can something as simple as mowing time really stop a turfgrass disease? In this episode of Turfgrass Epistemology, we look back at a landmark 1996 study by Williams, Powell, Vincelli, and Dougherty from the University of Kentucky — a paper that changed how superintendents think about dew, nitrogen, and dollar spot control.
Dollar spot (Sclerotinia homoeocarpa) thrives on leaf moisture. Williams et al. tested what happens when you simply remove that moisture early in the morning. Their data were stunning — mowing or “poling” to knock dew off reduced dollar spot by as much as 81% on fairways and 53% on greens. That’s before any fungicide was even applied. Add moderate nitrogen fertilization, and disease pressure dropped even further. Clipping removal, on the other hand, didn’t matter much.
This episode explores what these results mean for modern turf management. How does dew act as a bridge for fungal infection? Why does nitrogen strengthen bentgrass against disease? And what does this tell us about integrating simple cultural practices with fungicide programs? Join Dr. Travis Shaddox as we revisit this foundational study — proof that sometimes, the mower is mightier than the fungicide.
📘 Source: Williams, D.W., A.J. Powell Jr., P. Vincelli, and C.T. Dougherty. 1996. Dollar Spot on Bentgrass Influenced by Displacement of Leaf Surface Moisture, Nitrogen, and Clipping Removal. Crop Science 36:1304–1309.
🔬 Keywords: Dollar Spot, Bentgrass, Dew Removal, Nitrogen, Turfgrass Disease, Integrated ManagementDon’t forget to like, share, and subscribe to stay updated on more science-driven insights!
Become a member of Turfgrass Epistemology and support turfgrass research:www.youtube.com/@TurfgrassEpistemology/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf

S3 E54 The Rise and Fall of University Turfgrass Programs

In this video, I explore the history and current state of university turfgrass programs—from their rise during the post-war boom in golf, parks, and sports fields to their decline in recent decades. I explain how turfgrass faculty positions are created and filled, what factors lead to the loss of those positions, and why many programs are now disappearing altogether. I connect the dots between enrollment trends, industry funding, and the shifting priorities of universities that have left turfgrass science struggling to survive. Most importantly, I discuss what the turfgrass community—educators, managers, and industry leaders—can do to reverse the trend and rebuild the academic foundation that once supported innovation in turf management. This episode blends history, data, and reflection to uncover how we got here and what it will take to bring turfgrass education back.

S3 E53 Does Biochar Reduce Dollar Spot?

In this video, I examine the 2021 study by Beckley and Roberts published in the International Turfgrass Society Research Journal titled “Utilizing Organic Amendments for General Suppression of Dollar Spot on Creeping Bentgrass.” The discussion centers on one key question: Does biochar actually reduce dollar spot? I break down the experimental design—how researchers compared biochar, compost, vermicompost, and traditional fertilizers under equal nitrogen rates—and explains what the data really show. Were the reductions in dollar spot due to microbial changes, or simply better nitrogen nutrition? You’ll see how biochar performed across two years, why the results were inconsistent, and what this means for turfgrass managers trying to reduce fungicide use. The episode also explores the broader implications for integrated disease management and the growing interest in “natural” amendments. If you’ve ever wondered whether biochar is a biological breakthrough or just another overhyped input, this deep dive into the data will help separate evidence from assumption.
https://doi.org/10.1002/its2.55
Don’t forget to like, share, and subscribe to stay updated on more science-driven insights!
Become a member of Turfgrass Epistemology and support turfgrass research:www.youtube.com/@TurfgrassEpistemology/join
Voicemail:859-444-4234
Apple Podcasthttps://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379
Spotify Podcasthttps://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI
iHeart Radio Podcasthttps://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/
Podbeanhttps://turfgrassepistemology.podbean.com/
Online consultingCalendly.com/TravisShaddox
TwitterTwitter.com/TravisShaddox
EmailTravisShaddox@gmail.com
Turfgrass Programs and Extension Service Information:https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf